The romantic distress that results, as both women fall for Brian’s self-effacing charm, requires a certain suspension of disbelief: only a very tone-deaf Englishman could confuse these voices. Happily, it requires no stretch at all to succumb to Garofalo’s charm, wit and brainy sensuality. It’s a tricky challenge playing a woman who must be both unglamorous and irresistible, but Garofalo, with her unforced comic timing, makes it look easy. (Contrast the unfortunate casting of TV talk-show host Ricki Lake in the laborious “Mrs. Winterbourne”–a romantic comedy that fails to convince us its duckling is really a swan.) Garofalo, a standout in “Reality Bites,” may be the most welcome new romantic comedienne since Diane Keaton stole our hearts in “Annie Hall.”

Director Michael Lehmann (“Heathers”) nimbly keeps this airy concoction afloat, coaxing a funny performance out of Thurman as the clueless model with a penchant for loser boyfriends and a misguided ambition to be a newscaster. Just watching the Valkyrie-size Uma walking down the street with the compact Janeane is a sight gag in itself. The appealing Chaplin, making his American movie debut, hits just the right note of shaggy, self-deprecating charm. The fourth weapon in this small comedy’s arsenal is Brian’s Great Dane, Hank, a large drooling scene-stealer who does an exemplary job of acting on roller skates. “The Truth About Cats and Dogs” isn’t as magical as the Steve Martin/Fred Schepisi Cyrano spin “Roxanne,” but Wells and Lehmann get some up-to-the-moment resonance out of the conceit. Who hasn’t wrestled with the problem of getting your heart, your head and your desire to focus on the same object? And as for the phone-sex scene–not only is it titillating, it pays off at the end in a memorably unexpected Garofalo punch line.